Objective   To research the effect of sodium selenite on the action of cisplatin inhibiting transformation of human T lymphocytes, explore the influence of cisplatin and sodium selenite on rRNA gene transcription activity of lymphocytes and the relationship between transformation of T cells and rRNA gene transcription activity.

  Methods   Cisplatin was administered to the culture of lymphocytes after incubation for 24 hours with three different dosages(0.05, 0.2, 0.5 mg/L), the culture was also supplemented with sodium selenite(0.05 mg/L)at the beginning of the cell culture or at the same time as cisplatin was administered for different trea-t ment.The slide specimens were prepared using cytogenetical method after the cells were cultured for 72 hours, and then, the changes of the rate of transformation of T lymphocytes and frequencies of Ag-NORs, which reflect rRNA gene transcription activity, were investigated.

  Results   The rates of T lymphocyte transformation in the groups coneated with sodium selenite and cisplatin were significantly increased(P < 0.01-0.001)as compared with the groups without sodium selenite supplementation and suffering exposures to cisplatin alone at corresponding dose, up to or over the rate of negative control group.There were no significallt differences in the ratios of lymphocyte transformation between the groups pretreated by sodium selenite and the groups cotreated by sodium selenite with cisplatin, on condition that the other treatments were the same.There were no remarkable differences(P > 0.05)in the frequencies of AgNOR and satellite association among the all groups.

  Conclusion   Sodium selenite supplementation can preclude the inhibition of tranformation of T lymphocytes in vitro by cisplatin, regardless of pretreatment by sodium selenite or cotreatment with cisplatin, it is not time-dependent for sodium selenite precluding the inhibition of transformation of T lymphocytes by cisplatin.It is not clear the inflence of cisplatin or/and sodium selenite on rRNA gene transcription activity in normal human T lymphocytes and the relationship between T lymphocyte transformation and rRNA gene transcription activity.